The present invention relates generally to automotive electronics and in particular to a method of simplifying or eliminating wiring harnesses associated with advanced engine control and integrating engine control electronics with the vehicle engine.
Internal combustion engines used in automobiles and the like employ sophisticated engine control technologies making use of a variety of sensors and actuators in communication with microprocessor-based control circuitry. Engine control provided by these systems may provide increased performance, reduced emissions and higher reliability in the operation of the vehicle.
The microprocessor-based control circuitry may be located near the vehicle fire wall to provide a secure mounting of the circuitry away from the high temperature components of the engine and communicating with driver instrumentation in the passenger compartment.
The control circuitry communicates with a variety of sensors on or close to the engine including, for example, sensors for air mass flow, engine temperature, throttle position, engine speed and crankshaft position. The control circuitry, in receiving these sensor signals, produces actuator signals used to control throttle valves, fuel injectors, ignition coils and the like.
The sensors and actuators must be connected to the control circuitry by wiring and the wiring must be of a sufficient gauge to resist breaking under the tensile loads and flexure incident to normal service. The wires may be bound together in xe2x80x9charnessesxe2x80x9d to improve their mechanical resilience and may be sheathed to better resist abrasion.
Wiring harnesses represent a significant cost in the manufacture of a vehicle, not only in costs of material and manufacture, but also in costs of routing and connection to the sensors and actuators. Mechanically robust harnesses add weight to the vehicle affecting vehicle mileage and emissions. The harness with its attendant branching wire sets can increase the clutter of the engine compartment adversely affecting assembly, maintenance and repair of the engine.
The present invention provides an alternative to conventional wiring harnesses that use conductors supported and routed directly on engine components. These engine components guide, support and protect the conductors eliminating unneeded weight and structure incident to conventional harness systems. By eliminating separate harness structure, clutter in the engine compartment is substantially reduced.
The invention can also eliminate the separate assembly steps of attaching the harness to the engine components. This is done by incorporating control electronics directly on the engine structures (eliminating unnecessary points of attachment) and/or by incorporating connectors into the interfaces between engine structures so that mechanical assembly of the engine structures simultaneously accomplishes electrical connection. Engine components may be modified in design to improve their function as wiring support.
Specifically, then, the present invention provides interconnect circuitry system for use with a vehicle engine having control electronics communicating with engine mounted control devices. The interconnect circuitry system includes at least one structural engine component which when assembled to the vehicle engine presents a surface spanning a distance between the control electronics and at least one of the engine mounted control devices. Electrical conductors attach integrally to the surface of the structural engine component to be supported and guided thereby.
It is thus one object of the invention to eliminate the need for separate wiring harnesses by allowing structural engine components to provide interconnect circuitry between engine mounted control devices and control electronics.
The structural components may be, for example, an engine intake manifold, a valve cover, throttle body, air filter housing, or engine shrouding.
Thus it is another object of the invention to select engine components that naturally span the distance between common interconnected devices.
It is yet another object of the invention to provide for an extremely stiff and inelastic support for the conductors such as reduces the need for large gauge conductors.
The electrical conductors may be metal plated on the structural component and etched appropriately or may be preformed metal conductors molded into a molded polymer forming the structural component or may be adhesively or mechanically bonded to the surface of the structural component.
Thus it is another object of the invention to provide simple means for attaching conductors directly to an engine structure with the minimum necessary conductor and additional material.
At least one electrical connector may be integrally attached to the structural component electrically communicating with the electrical conductors.
Thus it is another object of the invention to permit multiple mechanically separable structural components to be fit together to provide interconnect circuitry between devices. It is another object of the invention to allow a structural component to form a portion of the interconnect circuitry between components.
It is another object of the invention to permit the devices to be easily detachable from the interconnect circuitry of the structural component for repair and the like.
The electrical conductors may provide exposed bonding surfaces and the invention may further include bonding solid-state circuitry to the bonding surfaces and integrally to the structural components.
Thus it is another object of the invention to allow the structural components to support not only conductors but also integrated circuits and other circuit components eliminating the need for separate circuit support structure (such as a circuit board) and the need for separate connections to the control circuitry.
The electrical connectors may be positioned at a point of attachment of the structural component with other engine parts so as to electrically connect to electrical conductors on the other engine parts when the structural component is mechanically attached to the other engine components.
Thus it is another object of the invention to allow the single step of mechanically attaching engine components to also provide for electrical connection of various components to each other.
The foregoing and other objects and advantages of the invention will appear from the following description. In this description, reference is made to the accompanying drawings which form a part hereof, and in which there is shown by way of illustration, a preferred embodiment of the invention. Such embodiment does not necessarily represent the full scope of the invention, however, and reference must be made therefore to the claims for interpreting the scope of the invention.